Prostate Tissue Homogenate Research Articles

Infiltration of inflammatory factors induced penile damage in chronic prostatitis.

The present study aimed to investigate the mechanism of penile damages in experimental autoimmune prostatitis (EAP) rat models to reveal the potential pathological mechanism of the relationship between CP and penile damages. Sprague-Dawley (SD) rats were administered with different concentrations of prostate tissue homogenate supernatant (PTHS) by multipoint subcutaneous injection to establish EAP models. IHC staining was done to assess the expression of inflammatory cytokines in prostate tissues and the corpus cavernosum of penis. Masson and Tunel staining was conducted to observe the fibrosis and apoptosis in the corpus cavernosum. Finally, the functional changes of corpus cavernosum were assessed by WB and IHC staining. The results revealed that EAP rats with different prostatitis severity were successfully established by PTHS. The expression of IL-1β, IL-6 and TNF-α in prostate tissues increased with the concentration of PTHS. The results of Masson and Tunel staining indicated fibrosis and apoptosis gradually aggravated in corpus cavernosum among different subgroups. The function of cavernosum impaired by prostatitis from WB and IHC results and positively with the severity. In conclusion, there existed the infiltration of inflammatory factors and impaired function in the corpus cavernosum of EAP rats' penis and positively correlated with the severity of prostatitis.

Impact of Cernitin™ on induced chronic prostatitis in animal model for understanding management of lower urinary tract symptoms

BackgroundCernitin™ pollen extracts (brand name Cernilton®) alleviates symptoms related to common lower uro-genital tract disorders in men. The underlying mechanisms are ill-defined but the inflammatory pathway could be one of them. In a previous in vitro study it was shown that Cernitin™ induce a regulatory effect on inflammatory parameters. MethodsIn this study, male Sprague Dawley rats were used to validate the effects of Cernitin™ in chronic prostatitis and benign prostatic hyperplasia. Pain was assessed by von Frey assay. ResultsCernitin™ exhibited significant pain relief in the induced prostatitis rat model and was associated with a significant decrease in the intraprostatic level of COX-2 and MCP-1 in the prostatic tissue homogenates. In a parallel study, Cernitin™ treatment led to a significant decrease in prostate weight in rats with testosterone induced BPH. Concurrently, a significant decrease in the percentage of proliferation marker, Ki-67, and androgen receptor expressing cells was observed. Similarly, a low level of cytoplasmic 5α-reductase expression was observed in Cernitin™- and finasteride-treated animals. ConclusionThe current in vivo experiments support the use of Cernitin™ as an anti-inflammatory and symptom reducing agent that could, in part, explain the impact of Cernitin™ on the management of chronic pelvic pain in men.

Comparison between selected hormone and protein levels in serum and prostate tissue homogenates in men with benign prostatic hyperplasia and metabolic disorders

PurposeThe purpose of the study was to assess the relationship between changes in the levels of selected hormones in serum and prostate tissue homogenate in regard to metabolic disorders in patients with diagnosed, surgically treated benign prostatic hyperplasia (BPH).Patients and methodsThe study involved a group of 154 men with a diagnosis of BPH with metabolic syndrome (MetS) and without MetS. The serum levels of the hormones – total testosterone, free testosterone, insulin, dehydroepiandrosterone sulfate, estradiol, luteinizing hormone, sex hormone binding globulin (SHBG), and insulin-like growth factor-1 (IGF-1) – were determined using the ELISA method. Prostate tissue sections obtained from the patients during transurethral resection of the prostate were frozen in liquid nitrogen. We determined the levels of the same hormones.ResultsThere was a statistically significant difference between the groups in terms of serum SHBG levels, but not in the prostate tissue SHBG levels. A similar relationship was observed in regard to IGF-1, the serum levels of which were significantly higher in patients with MetS. MetS had an effect on the ratio of hormone levels in serum to their levels in the prostate tissue. Correlations between the levels of biochemical parameters and the levels of hormones in serum and the prostate tissue of BPH patients with and without MetS demonstrate that serum SHBG levels correlated weakly with waist size and triglyceride levels.ConclusionThe occurrence of MetS in BPH patients was associated with changes in the levels of hormones and proteins. These changes, however, were not always equivalent to changes in the levels of these parameters in prostate tissue. It should also be mentioned that MetS in BPH patients had an influence on a quantitative balance between the levels of SHBG in serum and prostate tissue.

Identification and preliminary study of immunogens involved in autoimmune prostatitis in human males.

Experimental models have confirmed that autoimmunity is an important factor in the onset of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS); however, there is no conclusive evidence on whether autoimmune prostatitis exists in human males. Rabbits were immunized with either human prostate tissue homogenates or normal saline and the antiserum was collected. Two-dimensional electrophoresis (2-DE) was performed on the homogenates and Western blotting was conducted on the sera. The identified human prostate tissue immunodominant antigens (HPTIAs) were detected by mass spectrometry. The serum immunoglobulin (Ig)G from the immunized rabbits was purified with protein A-agarose, and the purified IgG was linked with Sepharose to purify HPTIAs by affinity chromatography. Non-obese diabetic (NOD) mice were immunized with the purified HPTIAs, and the levels of serum antibodies, INF-γ, and histopathological changes in their prostate tissues were detected. The purified HPTIAs were coated into polystyrene pores and serum autoantibodies in CP/CPPS patients were detected by enzyme-linked immunosorbent assay (ELISA). Meanwhile, serum interleukin 2 (IL-2), interferon gamma (IFNγ), and tumor necrosis factor alpha (TNFα) levels in CP/CPPS patients were also determined by ELISA. Sixteen HPTIAs were identified. Among them, three types were reported to be associated with prostatic diseases. Prostatitis was induced in mice immunized with the 16-HPTIA complex, with positive serum autoantibody and increased prostatic IFN-γ levels. The positive rate of serum autoantibodies against HPTIAs was significantly higher in CP/CPPS patients (23.1%, 18/78) than in the control (2.7%, 2/75). But there was no significant difference in serum TNFα, IFNγ, and IL-2 levels between the CPPS patients with positive and negative autoantibodies against HPTIAs. Autoantibodies against HPTIAs exist in part in CP/CPPS patients, which implies that autoimmunity and the 16 HPTIAs are important factors in the onset of CP/CPPS. The detection of serum autoantibodies could be applied in clinical diagnoses of autoimmune prostatitis; treatment protocols might change. Additional studies are needed to determine which of the 16 HPTIAs is the most important.

Histopathological classification criteria of rat model of chronic prostatitis/chronic pelvic pain syndrome.

A variety of murine models of experimental prostatitis that mimic the phenotype of human chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) have been developed. However, there is still a lack of explicit diagnosis criteria about those animal model. Our study is to establish histopathological classification criteria, which will be conducive to evaluate the animal models. We firstly established a rat model of experimental autoimmune prostatitis that is considered a valid model for CP/CPPS. For modelling, male Sprague-Dawley rats were immunized with autologous prostate tissue homogenate supernatant emulsified with complete Freund's adjuvant by subcutaneous injection into abdominal flank and simultaneously immunized with pertussis-diphtheria-tetanus vaccine by intraperitoneal injection. Three immunizations were administered semimonthly. At the 45th day, animals were killed, and prostate tissues were examined for morphology. Histologically, the prostate tissues were characterized by lymphoproliferation, atrophy of acini, and chronic inflammatory cells infiltration in the stromal connective tissue around the acini or ducts. Finally, we built histopathological classification criteria incorporating inflammation locations (mesenchyme, glands, periglandular tissues), ranges (focal, multifocal, diffuse), and grades (grade I-IV). To verify the effectiveness and practicability of the histopathological classification criteria, we conducted the treatment study with one of the alpha blockers, tamsulosin. The histopathological classification criteria of rat model of CP/CPPS will serve for further research of the pathogenesis and treatment strategies of the disease.

Influence of freeze-drying on the recovery of the tumour invasion markers uPA and PAI-1 from prostate cancer resections.

Urokinase plasminogen activator (uPA) and its inhibitor (PAI-1) have been shown to be of merit as biomarkers for a variety of cancers. Prostate tissue resections from patients with prostate cancer (PCa) and benign prostatic hyperplasia were analysed to determine the influence of freeze-drying on the recovery of uPA and PAI-1 and their predictive performance. Prostate tissue was frozen in liquid nitrogen and homogenised into a fine powder in a precooled stainless steel punch homogeniser. One aliquot of the powder was extracted directly, and a second aliquot was freeze-dried overnight and then extracted. The extracts were analysed by FEMTELLE assay to determine the concentrations of uPA and PAI-1. uPA/PAI-1 ratios were calculated for each sample, and the mean ratios for the frozen and the lyophilised tissue were compared. The concentrations of uPA measured for the frozen and lyophilised samples are strongly correlated (R = 0.90 ± 0.05). The same applies to the PAI-1 measured (R = 0.89 ± 0.03). The uPA/PAI-1 ratios for the lyophilised and frozen samples were strongly correlated. The uPA/PAI-1 ratios for frozen and lyophilised samples were found to be essentially the same with values of 0.0344 ± 0.0066 and 0.0340 ± 0.0068, respectively (P = 0.9633). The recovery of uPA and PAI-1 from a deep frozen prostate tissue homogenate followed by freeze-drying proceeds with a loss of 10 and 11%, respectively, with no influence on the uPA/PAI-1 ratio. Lyophilisation is a safe procedure for the preservation of frozen prostate tissue samples as it permits recovery of the markers without compromising their use for diagnostic purposes.

Influence of Kudou Shencha decotion on INF-γ, ICAM-1, MCP-1 levels of prostate tissue homogenate in immunity prostatitis model rats

Influence of Kudou Shencha decotion on INF-γ, ICAM-1, MCP-1 levels of prostate tissue homogenate in immunity prostatitis model rats

울금 추출물의 5-Alpha Reductase II 활성 저해 효과

5-Alpha reductase Ⅱ, which converts testosterone (T) to dihydrotestosterone (DHT), is a crucial enzyme Ⅱ in benign prostatic hyperplasia. Inhibitory effects of Curcuma longa L. (CL) extracts on 5-alpha reductase Ⅱ activity were investigated in rat prostate tissue homogenates as well as LNCaP cells expressing human 5-alpha reductase Ⅱ. Hot water extract (CL-HW) of Curcuma longa L. significantly inhibited 5-alpha reductase activity by over 80% at a concentration of 100 μg/mL, whereas 20% ethanol extracts (CL-E20) of Curcuma longa L. exhibited significant inhibitory activity from 50 μg/mL. These results indicated that Curcuma longa L is a potent 5-alpha reductase Ⅱ inhibitor for benign prostatic hyperplasia treatment.

Anticancer activity of the ethanolic extract of Crateva nurvala bark against testosterone and MNU-induced prostate cancer in rats

AimIn the present study the anticancer activity of the ethanolic extract of Crateva nurvala bark was evaluated against testosterone and N-methyl-N-nitrosourea (MNU)-induced prostate cancer in male Wistar rats. MethodsProstate cancer was induced in rats by the injection of testosterone for 3 d followed by injection of the chemical carcinogen MNU for 1 week. The prostate cancer-induced rats were treated with the ethanolic extract of C. nurvala bark, and testosterone injection was also continued through the experimental period of 4 months. Biochemical estimations including prostatic acid phosphatase, lipid peroxidation, enzymic antioxidants and non-enzymic antioxidants activity were done in the prostate and seminal vesicle tissue homogenate. ResultsThere was a significant increase in the level of acid phosphatase and lipid peroxidation in prostate cancer-induced rats, and after treatment with C. nurvala extract a significant decrease in the level of acid phosphatase lipid peroxidation were observed. The enzymic and non-enzymic antioxidants were decreased in the prostate cancer induced group and after treatment they were restored to near normal values. Histopathological examination showed significant changes such as hyperplastic prostatic acini and malignant proliferation of ductal epithelial cells in the prostate and seminal vesicle of carcinogen induced rats. After treatment with C. nurvala extract normal and flow-dilated ducts and acini with regular epithelial lining were observed in the prostate and partially hyperplastic and partially flattered epithelium were observed in seminal vesicles. ConclusionThe ethanolic extract of C. nurvala has significant anticancer activity evaluated by in an in vivo model.

Increased Inflammatory Factors Activity in Model Rats with Experimental Autoimmune Prostatitis

Male rats were immunized with prostate tissue homogenate supernate (PTHS) of male rats with complete Freund's adjuvant (CFA) intra dermal in the multiple points and simultaneously immunized with 0.5 ml Pertussis-Diphtheria-Tetanus (PDT) vaccine intra peritonea on 0 and 30th day. At the 45th day after first immunization, animals were sacrificed and a series of examinations such as HE stain, assay of TNF-alpha by ELISA and assay of inducible nitric oxide synthase (iNOS) mRNA by in-situ hybridization (ISH) were taken. We observed that there was a remarkable up-regulation of TNF-alpha expression in the high dosage model group. The results of macropathology, histopathology and iNOS ISH also revealed the same tendency. This experimental procedure is effective to induce chronic abacterial prostatitis (CAP).

Effects of various pesticides on human 5α-reductase activity in prostate and LNCaP cells

Certain pesticides are able to disturb the sex steroid hormone system and to act as antiandrogens. While the different underlying mechanisms remain unclear, inhibition of 5α-reductase, the enzyme which is indispensable for the synthesis of DHT and thus normal masculinization, appears to be one of the sensitive targets for endocrine disruption. We therefore tested several endocrine disrupters with antiandrogenic effects in vivo for their influence on 5α-reductase activity in two different test systems: (a) an enzyme assay with human Lymph Node Carcinoma of Prostate (LNCaP) cells and (b) an enzyme assay with human prostate tissue homogenate. The selected pesticides and industrial compounds were monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), triphenyltin (TPT), diuron, fenarimol, linuron, p, p′DDE, prochloraz and vinclozolin. The synthetic androgen methyltestosterone and the synthetic antiandrogen flutamide, as well as the 5α-reductase inhibitor finasteride served as control compounds. The effect of the organotin compounds DBT, TBT and TPT on enzyme activity was approximately the same in both test systems, with IC 50 values ranging between 2.7 and 11.2 μM, while in prostate tissue, methyltestosterone and prochloraz proved to be stronger inhibitors (IC 50 values of 1.9 and 12.4 μM) than in LNCaP cells (IC 50 values of 13.2 and 53.2 μM). The inhibitory impact of finasteride was approximately 130 times stronger in prostate tissue than in LNCaP cells. Fenarimol, flutamide, linuron and p, p′DDE inhibited 5α-reductase activity only at very high concentrations (IC 50 ⩾ 24 μM) in prostate homogenates, and not at all in LNCaP cells. On average, the IC 20 values were 3.5 times lower than the IC 50 values. Diuron, MBT and vinclozolin exerted no effect in either of the test systems. The finding of pesticides acting as 5α-reductase inhibitors might be of clinical relevance. As a screening tool for putative ED, the tissue assay is the more practical and sensitive method. However, the cell assay can, to some extent, reflect particular cell processes since the living cell is able to compensate moderate toxicological effects of the ED on cell viability, and possibly also their impact on 5α-reductase activity.

Acid phosphatase in prostatic tissue homogenates from patients with benign prostatic hyperplasia and prostatic carcinoma.

Acid phosphatase activity biochemically in the primary tumor of 20 patients with prostatic carcinoma, was studied in an attempt to understand the basis for a correlation or lack of correlation between serum and/or bone marrow acid phosphatase levels and the presence and/or clinical behavior of prostatic carcinoma. The enzyme activity was similarly measured in 19 patients with benign prostatic hyperplasia as controls. On the average, enzyme activities were lower (P less than 0.002) in the tissues from patients with carcinoma. There was no correlation of enzyme activity in tumor with the age of the patient, stage of disease, degree of differentiation of the tumor, or serum acid phosphatase activity.

Identification of dehydroepiandrosterone metabolites formed from human prostate homogenate using liquid chromatography–mass spectrometry and gas chromatography–mass spectrometry

The identification of the in vitro metabolites of dehydroepiandrosterone formed from human prostate homogenate was investigated by hyphenated techniques using the stable-isotope dilution method. A mixture of dehydroepiandrosterone and [ 2H 4]dehydroepiandrosterone was incubated with hypertrophied human prostate tissue homogenate in the presence of NAD, NADH and NADPH. The metabolites were extracted with AcOEt–hexane, purified by solid-phase extraction, and then analyzed by LC–atmospheric pressure chemical ionization MS and/or GC–MS. Androst-5-ene-3β,17β-diol (major product), androst-4-ene-3,17-dione, testosterone, 5α-dihydrotestosterone, androsterone, and 7α-hydroxydehydroepiandrosterone were identified in comparison with authentic samples based on their chromatographic behavior and mass spectra.

In vitro inhibition of testicular delta 5-3 beta-hydroxysteroid dehydrogenase and prostatic 5 alpha-reductase activities in rats and humans by strogen forte extract.

Clinical findings indicate that Strogen forte (a standardized extract of the plant Sabalis serrulata) can be use successfully in the medical treatment of benign prostatic hyperplasia. The aim of the present study was to investigate the possible inhibitory effects of the Strogen forte extract on rat and human testicular delta 5-3 beta-hydroxysteroid dehydrogenase (delta 5-3 beta-HSD) and prostatic 5 alpha-reductase (5 alpha-R). Strogen forte proved to be a direct inhibitor of medium effectivity, with similar IC50 values for rat testicular delta 5-3 beta-HSD (400 +/- 23 micrograms/ml) and human testicular delta 5-3 beta-HSD (212 +/- 8.6 micrograms/ml). 5 alpha-R activities were analysed by in vitro incubation of rat and human prostatic tissue homogenates with 14C-labelled testosterone as substrate in KRPG-DTT medium (pH = 7.4) with NADPH coenzyme, in air, at 37 degrees C, in the presence of Strogen forte extract. The results clearly demonstrate that Strogen forte is a potent inhibitor of prostatic 5 alpha-R, with IC50 values of 385 +/- 35.6 micrograms/ml for rat and 245 +/- 64.6 micrograms/ml for human prostatic 5 alpha-R. The present study has revealed that this plant extract inhibits not only prostatic 5 alpha-R, but also testicular delta 5-3 beta-HSD.

Inhibition of 5 alpha-reductase in genital skin fibroblasts and prostate tissue by dietary lignans and isoflavonoids.

Isoflavonoids and lignans, constituents of many plant foods, have been proposed as protective agents in those populations with a low incidence of hormone-dependent cancers. They may act by their inhibition of the metabolism of growth-promoting steroid hormones. This report describes the inhibition of 5 alpha-reductase and 17 beta-hydroxysteroid dehydrogenase by six isoflavonoids and two lignans in human genital skin fibroblast monolayers and homogenates, and in benign prostatic hyperplasia tissue homogenates. In genital skin fibroblasts, genistein, biochanin A and equol were the most potent inhibitors of 5 alpha-reductase activity, each resulting in greater than 80% inhibition at a concentration of 100 microM. The IC50 values for genistein and a seven-compound mixture were approximately 35 microM and 20 microM (2.9 microM of each compound) respectively. Of the lignans, enterolactone was the most potent inhibitor. Inhibition by biochanin A was shown to be reversible. When genital skin fibroblast homogenates were used, biochanin A was found to inhibit 5 alpha-reductase isozymes 1 and 2 to differing extents (30% and 75% respectively). Genistein was shown to inhibit 5 alpha-reductase 2 in a non-competitive nature (Vmax and Km values without and with inhibitor were 30 and 20 pmol/mg protein per h and 177 and 170 nM respectively). All of the compounds tested inhibited 17 beta-hydroxysteroid dehydrogenase activity in genital skin fibroblast monolayers. When prostate tissue homogenates were used, the compounds tested were better inhibitors of 5 alpha-reductase 1 than 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization and Localization of Prostatic Alpha1 Adrenoceptors Using Radioligand Receptor Binding on Slide-Mounted Tissue Section

Alpha1 adrenoceptor binding sites have been characterized in prostatic tissue homogenates using radioligand receptor binding studies. The objective of the present study was to characterize and localize prostatic alpha1 adrenoceptor binding sites using slide-mounted tissue sections and the ligand 3H-prazosin. The present study demonstrated that preincubation is not required; the optimal incubation interval is 40 minutes; and a 1-minute wash (once or twice) maximizes the proportion of specific 3H-prazosin binding. Saturation studies were performed at 8 different concentrations of 3H-prazosin ranging between 0.0625nM. to 8.0nM. The binding of 3H-prazosin was consistently saturable and of high affinity. The mean Kd and Bmax determined from 6 saturation studies was 4.16 × 10−10M. and 1.30fmol./mg. wet weight, respectively. The pharmacology of these 3H-prazosin binding sites was characterized using competitive displacement experiments. The mean IC50 corrected for prazosin, phentolamine and yohimbine was 7.8 × 10−10M., 6.0 × 10−10M. and 2.1 × 10−10M. The rank order of the IC50 corrected values indicates that alpha1 binding sites were measured under the assay conditions. In the present study, the mean values for Kd, Bmax and IC50 corrected are similar to values previously reported using prostatic tissue homogenates. Prostatic tissue sections were apposed to x-ray film after being incubated with 3nM. 3H-prazosin (total prazosin binding) and 3nM. 3H-prazosin + 8 μM. prazosin (nonspecific prazosin binding). The autoradiograms were analyzed using a computerized analyzing system. The specific radioactive densities of 3H-prazosin in the stroma and glandular epithelium were 1099 ± 48pCi/mg. and 163 ± 42pCi/mg. The present study validates the technique of assaying alpha1 adrenoceptor binding sites on slide-mounted prostatic tissue sections and provides further evidence that alpha1 adrenoceptor binding sites are localized primarily to the stromal elements of the prostate.

Immunological comparison between prostate-specific antigen and ?-seminoprotein

Prostate-specific antigen (PA) and gamma-seminoprotein (gamma-Sm) were compared by immunocytochemical, immunodiffusion and immunoblotting methods using rabbit anti-PA antibody and rabbit anti-gamma-Sm antibody. Enzyme immunoassays (EIAs) were developed for measurements of PA and gamma-Sm to determine a correlation between serum PA and gamma-Sm levels in patients with prostate cancer. The patterns of localization and distribution of PA and gamma-Sm were identical in prostate tissue sections, including benign and cancerous human prostates. The immunodiffusion study showed that the antigens with which anti-PA antibody and anti-gamma-Sm antibody reacted in seminal plasma and prostate tissue homogenates were identical to each other. In the immunoblotting study, anti-PA antibody and anti-gamma-Sm antibody recognized a single antigen corresponding to a molecular weight of approximately 33,000 both in seminal plasma and prostate tissue homogenates. The EIAs developed in this study were sensitive, specific, and reproducible, and the correlation between serum PA and gamma-Sm values determined by these EIAs was highly significant (r = 0.99, P less than 0.001). These results indicated that PA and gamma-Sm were immunologically identical and that serum PA and gamma-Sm determined by immunoassays using anti-PA antibody and anti-gamma-Sm antibody should be evaluated as identical tumor markers for serodiagnosis of prostate cancer.

Partial characterization of a thyroid‐stimulating hormone‐like peptide in neuroendocrine cells of the human prostate gland

Immunohistochemical identification of the most prevalent type of neuroendocrine (NE) cells in the human prostate gland can be made with polyclonal antisera against human thyroid-stimulating hormone (TSH). A TSH-like peptide was characterized by analysis of prostatic tissue homogenates with sodium dodecyl sulfate-polyacrylamide gel (SDS-PAGE) electrophoresis followed by immunoblotting. A single protein band, with an apparent mass of about 32 kDa after reduction, was identified both with polyclonal antisera against human TSH and with a polyclonal antiserum raised against a synthetic peptide corresponding to the carboxyterminal part of the beta-subunit of human TSH. The TSH-like prostatic peptide identified here is, on the basis of its molecular mass and absence of immunoreactivity with an antiserum raised against a synthetic peptide representing the mid-portion of the beta-subunit of TSH, not identical with the pituitary beta-subunit of TSH. On the other hand, this 32 kDa prostatic peptide may have certain structural elements in common with the pituitary beta-subunit of TSH, since it is recognized both with polyclonal antisera against TSH and with an antiserum against the carboxyterminal part of the beta-subunit of TSH.

Simultaneous Determination of Testosterone, Dihydrotestosterone and 5α‐Androstan‐3α,‐17β‐Diol by Isotopic Dilution Mass Spectrometry in Plasma and Prostatic Tissue of Patients Affected by Benign Prostatic Hyperplasia Effects of 3‐Month Treatment with a GnRH Analog

This article reports an isotope dilution mass spectrometric method for the simultaneous measurement of testosterone (T), dihydrotestosterone (DHT), and 5 alpha-androstan-3 alpha, 17 beta-diol (3 alpha-diol) in human plasma and prostatic tissue. After addition of tri-deuterated steroids as internal standards to prostatic tissue homogenates or plasma samples, extraction was performed with diethylether. The extracts were purified by two chromatographic steps (Sep-Pak C 18 cartridge and Sephadex LH-20) and injected into a gas chromatograph coupled with a mass spectrometer after derivatization with heptafluorobutyric acid. This method was highly specific and showed good precision, accuracy, reproducibility and sensitivity. T, DHT, and 3 alpha-diol were measured in human plasma and in prostatic tissue of seven patients with benign prostatic hyperplasia (BPH) treated for 3 months with a long acting GnRH analog before surgery. Plasma levels of T, DHT, and 3 alpha-diol were reduced by GnRH analog treatment to castrate levels. The tissue concentrations of the same steroids, compared with those obtained from 19 untreated patients, showed a mean reduction of about 90% for DHT and 3 alpha-diol, and about 75% for T. These results suggest that about 90% of prostatic DHT and 3 alpha-diol depend on testicular activity because they are dramatically reduced after pharmacologic castration.

Alpha2 Adrenergic Receptors in Hyperplastic Human Prostate: Identification and Characterization Using [3H] Rauwolscine

[3H] Rauwolscine ([3H]Ra), a selective ligand for the alpha2 adrenergic receptor, was used to identify and characterize alpha2 adrenergic receptors in prostate glands of men with benign prostatic hyperplasia. Specific binding of [3H]Ra to prostatic tissue homogenates was rapid and readily reversible by addition of excess unlabelled phentolamine. Scatchard analysis of saturation experiments demonstrates a single, saturable class of high affinity binding sites (Bmax = 0.31 ± 0.04 fmol./μg. DNA, Kd = 0.9 ± 0.11nM.). The relative potency of alpha adrenergic drugs (clonidine, alphamethylnorepinephrine and prazosin) in competing for [3H]Ra binding sites was consistent with the order predicted for an alpha2 subtype. The role of alpha2 adrenergic receptors in normal prostatic function and in men with bladder outlet obstruction secondary to BPH requires further investigation.